Circuit interrupters



Jan. 28, 1958- w. M. LEEDS 2,821,608

CIRCUIT INTERRUPTERS Filed Dec. 8, 1954 5 Sheets-Sheet 1 Fig.|.

Fig.2.

Jan. 28, 1958 w. M. LEEDS 2,821,608

CIRCUIT INTERRUPTERS Filed Dec. 8, 1954 5 Sheets-Sheet 2 F I II A 53 g 49 55H Jan- '28, 195 w. M. LEEDS 2,821,608

CIRCUIT INTERRUPTERS Filed Dec. 8, 1954 3 Sheets-Sheet 3 Fig. 8.

SDI

glmsssesz INVENTOR v Wmthro M. Leeds. %/l. M B p CIRCUIT INTERRUPTERS Winthrop M. Leeds, Forest Hills, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application December 8, 1954, Serial No. 473,938

Claims. (Cl. 200-150) and assigned to the assignee of the instant application,

there is disclosed and claimed a high-voltage circuit interrupter, in the particular instance disclosed, adapted for 330 kv. and for an interrupting capacity of 25 million kva. In the particular interrupting assembly described in the aforesaid application, the movable contacts @tates Patent 0 are arranged axially along the length of the interrupting assembly, and are actuated by a pair of longitudinallyextending insulating operating rods, the movable contacts being secured to bridging members, the latter bridging the pair of operating rods and being movable therewith. v

Necessarily, the length of the interrupting assembly under such conditions is relatively long, and to adapt the interrupting assembly for still higher voltages, and perhaps even higher interrupting capacities, it is desirable to conserve the axial length along the interrupting assembly.

It is a further object of my invention to shorten the length of an interrupting assembly of the type set out in the aforesaid application, while at the same time retaining the advantages of having serially connected contacts and in addition having laterally removable arc-exposed within the interior of the interrupting tube, so that,

as a result, the movable contact rods will substantially clear adjacently disposed arc-extinguishing units.

, .Yet a further object of the invention is to provide an improved circuit interrupter in which the parts will be readily accessible, and, upon removal of the arc-extinguishing units, the exposed contact structures may be observed for wear.

Further objects and advantages will readily become apparent upon reading the following specification, taken in conjunction with the drawings, in which: Figure 1 is a side elevational view, with the tank partially broken away in vertical section, of one pole unit of a circuit interrupter embodying my invention, the contact structure being illustrated in the closed-circuit posi- 493 ice Fig. 2 is an enlarged vertical sectional view through the left-hand arc-extinguishing assemblage of Fig. 1, the contact structure likewise being shown in the closed-circuit position;

Fig. 3 is an inverted plan view, in section, taken substantially along the line IIIIII of Fig. 2;

Fig. 4 is a vertical sectional view through a modified type of arc-extinguishing assemblage, embodying three movable contact rods, the contact structure being shown in the closed-circuit position;

Fig. 5 is a plan view, in section, taken substantially along the line V-V of Fig. 4;

Fig. 6 is a plan view, in section, of a still further modified type of arc-extinguishing assemblage utilizing three movable contact rods;

Fig. 7 is a plan view, in section, taken substantially along the line VllVll of the interrupting assemblage illustrated in Fig. 8; and

Fig. 8 is a vertical sectional view through still a further embodiment of my invention utilizing tour movable contact rods, and the contact structure being shown in the closed-circuit position.

Referring to the drawings, and more particularly to Fig. 1 thereof, the reference numeral 1 designates a tank filled to the level 2 with a suitable arc-extinguishing fluid 3, in this particular instance circuit breaker oil. Supported by the cover or top 4 of the tank 1 are a pair of terminal bushings 5, 6, to the lower interior ends of which are supported arc-extinguishing assemblages, generally designated by the reference numeral 7, and electrically interconnected by a conducting cross bar 8. The cross bar 8 is vertically actuated, in a reciprocal manner, by an operating rod 9, which may be operated by any suitable mechanism, forming no part of my invention.

Referring to Figs. 2 and 3, which more clearly illustrate the internal construction of the arc-extinguishing assemblage 7, it will be observed that an adapter 11 (Fig. 1) has a pedestal 12 integrally formed therewith, to be clamped upon the lower end of the terminal stud, not shown, extending interiorly through the terminal bushing 5. Bolts 13 (Fig. 2) secure a top plate 14 rigidly in place, the top plate in turn being bolted by bolts 15 to a clamping flange 16, which is secured to the upper end of an interrupting tube 17. The interrupting tube 17 is formed of a strong insulating material having the requisite strength to Withstand considerable pressure within the arc-extinguishing assemblage 7.

As more clearly illustrated in Fig. 3, a pair of arc-extinguishing units 18 are mounted within the walls of the interrupting tube 17 at substantially right angles to each other. Each arc-extinguishing unit 18 is herein illustrated as being formed out of a single insulating block, but in practice it is desirable to use a laminated plate construction, each of the plates having the proper configuration for venting the extinguishing fluid out of the interrupting tube 17. As shown, each arc-extinguishing unit 18 has a pair of venting passages 20 associated therewith leading out of opposite ends of the unit 18. Also, a vertical arcing passage 21 is provided, through which movable contact rods 22, 23 pass, as more fully explained hereinafter. Preferably, an intermediately disposed pocket 24 is provided between the two venting passages 20.

As more fully explained in the aforesaid patent application, upon separation of the movable contact rod 22 from the relatively stationary contact 25, or upon the separation of the movable contact rod 23 from the intermediately disposed relatively stationary contact 26, an arc is drawn downwardly through the arcing passage 21 and is acted upon by the arc-extinguishing fluid 3, which completely penetrates all of the passages, the assemblage 'i' being submerged within the liquid 3.

,It will be noted that the two movable contact rods 22, 23 are of different lengths and are located off center of the axis of the interrupter so that the upper moving contact can pass beside the lower arc-extinguishing structure without passing through the arc passage thereof. The lower ends of these contact operating rods are rigidly secured together at their lower ends by a conducting cross bar 27, which is struck during the closing stroke by the extremity 28 of the movable bridging member 8. Also, compression springs 29 are provided, encircling the lower ends of movable contact rods 22, 23 to bias the movable contact assemblage, generally designated by the reference numeral 30, in a downward opening direction. The cross bar 27 has a laterally extending lug 31 which strikes an inwardly extending portion 32, integrally formed with the lower electrostatic shield 33, as more clearly shown in Figs. 4 and 8 of the drawings. This halts the opening movement of the contact rods 22, 23 at a point where the tips of the contact rods 22, 23 are just below the arc-extinguishing units 18. This permits the arc-extinguishing units 18 to be laterally removed from the tube 17 in the fully open-circuit position of the device. Although the movable contact rod 22, in this particular instance, is illustrated as engaging a notch 34 at the side of the lower arc-extinguishing unit 18, nevertheless, as will be obvious, the notch 34 could be eliminated by the unit 18 being made narrower so that contact rod 22 would clear lower unit 18 to permit lateral removal of lower unit 18.

To have the contacts 22, 25 and 23, 26 electrically in series, it is necessary to provide a current collector 35. This might be a flexible strap having one end secured to and movable with the upper rod contact 22, but may be, as illustrated in Fig. 2, a sliding contact finger arrangement, in which the finger contacts 36 are biased laterally by springs 37 against the sides of the movable contact rod 22. Also, it will be noted that the lower portion of the movable contact rod 22 is formed of insulating material, as at 38, so that the current carried by the movable contact 22 will be compelled to be collected by the current collector 35 and carried to the lower relatively stationary contact 26.

With this arrangement of off-set contact rods, partly of insulating material, it is not necessary to space the arc extinguishing units 18 apart a distance equal to or greater than the travel of the moving conducting portions of the rods since the upper conducting portion moves down beside the lower extinguishing unit. This makes possible a shorter interrupting structure for a given total break distance.

To lock the arc-extinguishing units 18 in place, notches 39 are provided at the lower sides of the units 18, and locking plates 40 abut thereagainst, being secured to the tube 17 by bolts 41, the latter also serving to support in place the current collector 3S and the relatively .sta-

.tionary contact structure 26. The removal of one lock- ;ing plate 40 only is suflicient to permit removal of the extinguishing unit 18 without releasing the current collector 35.

tact 22, current collector 35, to relatively stationary contact 26. The circuit then extends through movable contactrod 23 to conducting cross bar 27 and thence through the conducting bridging member 8 to the right-hand arc- ;extinguishing.assemblage 7 (Fig- 1), through which the circuit extends inaan identical manner, in reverse order.

4 to the terminal stud extending upwardly interiorly within the right-hand terminal bushing 6 of the interrupter.

During the opening operation, the insulating operating rod 9 is moved downwardly by suitable mechanism, either in response to manual initiation, or in response to overload conditions detected by overload relays, to cause corresponding downward opening motion of the bridging member 8. This permits the compression springs 29, associated with the two assemblages 7, to force the, pair of movable contact rods 22, 23 downwardly within each assemblage 7. Considering only the left-hand arc-extinguishing assemblage 7, it will be apparent that arcs will be established between the pairs of contacts 22, 25 and 23, 26, along the arcing passages 21 within the arcextinguishing units 18. These arcs will act upon the liquid, such as oil, disposed within the passage structure to evolve gas. This gas and liquid will be ejected outwardly along the venting passages 20 to the region externally of the assemblage 7, and the circuit will thereby be interrupted. The cross bar 27 will separate from the extremity 28 of the bridging member 8 following contact between the lug 31 and the stop 32 of the lower electrostatic shield 33. The bridging member 8 will then continue to move downwardly to the isolating position, indicated by the dotted lines 42 in Fig. 1.

It will be observed that the movable contact rods 22 and 23 move together as a unit, and thereby insure the drawing of the arcs at the proper time. It will also be observed that the upper unit 18 is laterally removable out of the interrupting tube 17 freely in the open-circuit position. Although the lower unit 18 is provided with a notch 34, by a suitable narrowing of the width of the lower unit 18, it likewise could be removed laterally out of the interrupting tube 17 without interference with the rod 22 in the open-circuit position. In addition, upon removing the bolts 43, which clamp a lower inverted cup-shaped plate member 44 from the lower mounting flange 45, the entire movable contact assemblage 30 may be removed downwardly completely out of the interrupting tube 17.

Referring more particularly to Figs. 4 and 5 of the drawings, which illustrate a modified type of arc-extinguishing assemblage 47, it will be observed that in this particular instance three rod-shaped movable contacts 48, 49, 50 of difierent lengths are employed to collectively form a movable contact assemblage, generally designated by the reference numeral 51. As observed in Fig. 5, the modified type of arc-extinguishing units 18a are positioned substantially at 60 angular degrees away from each other, and the lower two units 18a have small notches 34 to accommodate the movable contact rods 48, 49. By taking out the contact rods 48, 49, the lower extinguishing units 18a can be removed. However, as noted above, if it were desirable, the units 18a could be narrowed to completely clear the contact rods 48-50 to permit lateral removal thereof in the normal fully-open-circuit position of the contact structure 51. 'The arc-extinguishing assemblage 47 operates in a similar manner to'that of the interrupter of Figs. l-3, there merely being an additional current collector35 and three pairs of serially related contacts, namely relatively stationary contact 52, movable contact rod 48, relatively stationary contact 53, movable contact rod 49, and relatively stationary contact 54 cooperating with the front movable contact rod 50, as viewed in Fig. 4. Since the functioning of the device seems obvious in the light of the description pertaining to Fig. 2,further amplification appears unnecessary.

Fig. 6 illustrates a plan view, in section, of a modified type of assemblage 55, which may be identical to the assemblage 470i Figs. 4 and 5, but in thisparticularinstance the arc-extinguishing units 56 are of filightlydifferent construction to insure'that all of them may readily be laterally removed from the interrupting tube 17 inthe normal fully-open-circuit position of the interrupter. shown in Fig. 6, the modified type of arcextinguishing units 56 are vented only at one end,- along the vent passages a. The other end 57 of the arc-extinguishing units 56 have merely a guiding and supporting function, it being observed that thereis considerable clearance between the units 56 and the movable contact rods 48-50. The operation of the assemblage 55 is identical to that of the assemblage 47 in Figs. 4 and 5, with the exception that Venting takes place out of the units 56 only in one direction, as permitted by the unidirectional venting passages 20a.

Figs. 7 and 8 illustrate anothermodified type of arcextinguishing assemblage, generally designated by the reference numeral 59, and incorporating a plurality, in this particular instance four, movable contact rods 6063. Again, the four movable contact rods are tied together at their lower end by a cross bar 27a, which is actuated by the bridging member 8 during the closing stroke, and acted upon by the compression springs 29 during the opening stroke. It will be noted that the modified type of arcextinguishing units 64 are vented only at one end so that the movable contact rods may pass through the other ends thereof, as illustrated in Fig. 8.

It will be observed, from a study of Figs. 7 and 8, that the current passes from the relatively stationary contact 65 to the upper movable rod-shaped contact 60, thence through a current collector 66 to an intermediately disposed relatively stationary contact 67. The current then passes through the movable contact rod61 and thence by means of a current collector 68 to the relatively stationary contact 69. The circuit then extends through the righthand movable contact rod 62 to a third current collector 70, which is electrically connected to the lowermost relatively stationary contact 71. The circuit then passes downwardly through the front rod-shaped contact 63, as viewed in Fig. 8, which is the shortest in length of all four contact rods 60-63.

The operation of the modified arc-extinguishing assemblage 59 is similar to that previously described; consequently a further description appears unnecessary. It suflices merely to state that the modification of Figs. 7 and 8 is adapted for the higher voltage ratings, and the insulating portions 72, 73 and 74 associated respectively with the movable contact rods 60, 61 and 62 reduces the vertical, or axial length of the assemblage 59, thereby providing a more compact construction. In addition, it is noted that the units 64 may be identical in construction and interchangeable.

From the foregoing description of certain embodiments of my invention, it will be apparent that I have retained many of the advantages set out in the aforesaid application, and have retained the feature of having a removable fiber block for easy inspection of the contacts. I have provided a novel arrangement for operating the contacts and locating the fiber extinguishing blocks that provides a considerably shorter assembly than those available heretofore without giving up the principal advantages of the multi-break tubular construction. With the two-break arrangement illustrated in Figs. 1-3, I have oriented the interrupting blocks at substantially 90 with respect to each other. It will be noted that the contact rods 22, 23 were located off center, so that the upper moving contact 22 can pass the lower interrupting unit 18. The movable contacts are connected to the cross head 27 and accelerated by springs to the open position. Vents for gas and are products may be provided at the ends of the interrupting units, as in Figs. 2 and 4, or the vents may be provided at only one end of the units as in the constructions of Figs. 6 and 8.

I have shown how the principle can be extended to a three-break construction, as illustrated in Figs. 4 and 6, or even extended to four breaks in series as illustrated in Figs. 7 and 8. In the latter arrangement, the blocks 64 are vented at one end only so as to allow room for a movable contact to pass through the other end of the block. A still more compact three-break arrangement, vented atone end of the blocks only, is shown in Fig. 6 with the opposite end 57 trimmed down for guiding and support only. As set out in the aforesaid application, for certain applications, a pressure-generating gap may be provided at any one break by omitting the vents associated at that particular arc-extinguishing unit and providing suitable channels to transmit pressure from the gap to the interior of the main tubular chamber. 7

Although I have shown and described specific structures, it is clearly to be understood that the same were merely for the purpose of illustration, and that changes and modifications may be readily made therein, by those skilled in the art without departing from the spirit and scope of the invention.

1 claim as my invention:

1. A circuit interrupter including an interrupting tube, a movable contact assembly including three or more movable contact rods, a cross bar for mechanically connecting together the adjacent ends of the three or more movable contact rods, at least one of the contact rods having an insulating rod portion, a current collecting structure for the movable contact rod having an insulating rod portion, a plurality of arc-extinguishing units each providing venting exteriorly of the interrupting tube, at least one of the arc-extinguishing units having venting occurring only at one end thereof with the other end of the interrupting unit reduced in size to clear adjacent contact rods and serving a guiding function, and at least said one of the arc-extinguishing units being mounted in the side wall of the interrupting tube and laterally removable therefrom.

2. A circuit interrupter including an insulating interruping tube, four movable contact rods of different length movable axially within the tube, three of the four movable contact rods having insulating rod portions, a current collector associated with each movable contact rod having an insulating rod portion, a relatively stationary contact associated with the longest movable contact rod to establish an arc, three other relatively stationary contacts, each of which is associated with a current collector, a plurality of arc-extinguishing units of smaller external dimensions than the inside dimension of the interrupting tube each providing venting exteriorly of the interrupting tube, at least one of the arc-extinguishing units being mounted in the side wall of the tube and laterally removable therefrom, at least one of said movable contact rods substantially clearing the outer boundary of one of the arc-extinguishing units interiorly of the interrupting tube, and means for simultaneously moving the four movable contact rods.

3. A circuit interrupter including an interrupting tube, a movable contact assembly including two or more movable contact rods of different lengths, a cross bar for mechanically connecting together the adjacent ends of the two or more movable contact rods, at least one of the contact rods having an insulating rod portion, a current collecting structure for the movable contact rod havhaving an insulating rod portion, at least a pair of relatively stationary contacts, means electrically connecting one of the relatively stationary contacts to said current collecting structure, a plurality of arc-extinguishing units of smaller external dimension than the internal dimension of the interrupting tube each providing venting exteriorly of the interrupting tube, said units being mounted in the side wall of the tube and laterally removable therefrom, and at least one of the movable contacts rods substantially clearing the outer confines of an adjacently disposed arc-extinguishing unit.

4. A circuit interrupter including an insulating interrupting tube, a movable contact assembly including two or more movable contact rods of different lengths, a cross-bar for mechanically interconnecting together the adjacent ends of the two or more movable contact rods, at least one of the contact rods having an insulating rod "portion, 'a "current collecting structure for the movable contact rod having an insulating rod portion, a laterally removable arc-extinguishing unit-having its ends mounted in the side wall of said interrupting tube and associated with the contacting end of one of the movable contact rods, said arc-extinguishing unit causing venting to occur only adjacent one end thereof exteriorly of the tube, and the other non-venting end of said "arc-extinguishing unit being reduced in size to clear one or more adjacent contact rods and having purely a guiding function.

5. The combination in a circuit interrupter of an insulating elongated hollow interrupting tube, a movable contact assembly including two or more movable contact rods of different length movable axially of said interrupting tube, a cross-bar for mechanically connecting together the adjacent ends of said two or more movable Contact rods to insure their simultaneous movement, biasing 'rneans adjacent the cross-bar end of said movable contact rods for biasing them to the open-circuit position, one or more tubular arc-extinguishing units of smaller external dimension than the internal dimension of said 'hollow elongated interrupting tube and having their ends mounted in openings in the side Wall of said interrupting tube, said one or more arc-extinguishing units'extending transversely of the axis of said interrupting tube substantially diametrically across the interior of said hollow interrupting tube so as to provide a communicating space within said interrupting tube around the-external confines of the one or more arc-extinguishing units, at least one ofsaid"arc-extinguishnig units being doublevented and providing therebyventing in opposite directions exteriorly of said interrupting tube, at least one of said movable contact rods having an insulating rod portion, a relatively stationaryconta'ct cooperating with ashorter movable contact rod than the longest movable contact rod to establish arcing in one of said arc-extinguishing units, a current collecting structure forthemovable contact rod having an insulating rod portion which is electrically connected to said relatively stationary contact, said one or more arc-extinguishing units being laterally removable from the side wall of--said interrupting tube in the open circuit position of the movable contact assembly, and at least one of said movable contact rods having an insulating rod "portion being movable in said communicating space substantially clearing the outerboundary of said double-vented arc-extinguishing 'unit to eliminate friction and not to interfere with the double venting action of said arc-extinguishing unit.

References Cited infthe file of this patent UNITED STATES PATENTS 1,949,258 Paul Feb. 27, 1934 2,261,026 Crabbs Oct. 28, 1941 2,412,857 Baker Dec. 17, 1946 2,650,972 Kuwayama Sept. 1, 1953 2,673,272 Cushing Mar. 23, 1954 2,749,412 McBride et a]. June .5, 1956 

